Sleep Modes
Overview
ESP32-C2 supports two major power saving modes: Light-sleep and Deep-sleep. According to the features used by an application, there are some sub sleep modes. See Sleep Modes for these sleep modes and sub sleep modes. Additionally, there are some power-down options that can be configured to further reduce the power consumption. See Power-down Options for more details.
There are several wakeup sources in the sleep modes. These sources can also be combined so that the chip will wake up when any of the sources are triggered. Wakeup Sources describes these wakeup sources and configuration APIs in detail.
The configuration of power-down options and wakeup sources are optional. They can be configured at any moment before entering the sleep modes.
Then the application can call sleep start APIs to enter one of the sleep modes. See Entering Sleep for more details. When the wakeup condition is met, the application is awoken from sleep. See Checking Sleep Wakeup Cause on how to get the wakeup cause, and Disable Sleep Wakeup Source on how to handle the wakeup sources after wakeup.
Sleep Modes
In Light-sleep mode, the digital peripherals, most of the RAM, and CPUs are clock-gated and their supply voltage is reduced. Upon exit from Light-sleep, the digital peripherals, RAM, and CPUs resume operation and their internal states are preserved.
In Deep-sleep mode, the CPUs, most of the RAM, and all digital peripherals that are clocked from APB_CLK are powered off. The only parts of the chip that remain powered on are:
RTC controller
Wi-Fi/Bluetooth and Sleep Modes
In Deep-sleep and Light-sleep modes, the wireless peripherals are powered down. Before entering Deep-sleep or Light-sleep modes, the application must disable Wi-Fi and Bluetooth using the appropriate calls (i.e., nimble_port_stop()
, nimble_port_deinit()
, esp_bluedroid_disable()
, esp_bluedroid_deinit()
, esp_bt_controller_disable()
, esp_bt_controller_deinit()
, esp_wifi_stop()
). Wi-Fi and Bluetooth connections are not maintained in Deep-sleep or Light-sleep mode, even if these functions are not called.
If Wi-Fi/Bluetooth connections need to be maintained, enable Wi-Fi/Bluetooth Modem-sleep mode and automatic Light-sleep feature (see Power Management APIs). This allows the system to wake up from sleep automatically when required by the Wi-Fi/Bluetooth driver, thereby maintaining the connection.
Sub Sleep Modes
Tables below list the sub sleep modes in the first row and the features they support in the first column. Modes that support more features may consume more power during sleep mode. The sleep system automatically selects the mode that satisfies all the features required by the user while consuming least power.
Deep-sleep:
DSLP_ULTRA_LOW |
DSLP_DEFAULT |
DSLP_8MD256/ |
|
---|---|---|---|
DSLP_ADC_TSENS |
|||
ULP/Touch sensor (ESP32-S2 and ESP32-S3 only) |
Y |
Y |
Y |
RTC IO input/RTC memory at high temperature |
Y |
Y |
|
ADC_TSEN_MONITOR |
Y |
||
8MD256 as the clock source for RTC_SLOW_CLK |
Y |
Features:
RTC IO input/RTC memory at high temperature (experimental): Use RTC IO as input pins, or use RTC memory at high temperature. The chip can go into ultra low power mode when these features are disabled. Controlled by API
esp_sleep_sub_mode_config()
with ESP_SLEEP_ULTRA_LOW_MODE argument.ADC_TSEN_MONITOR: Use ADC/Temperature Sensor in monitor mode (controlled by ULP). Enabled by API
ulp_adc_init()
or its higher level APIs. Only available for ESP32-S2 and ESP32-S3 chips with monitor mode.8MD256 as the clock source for RTC_SLOW_CLK: When 8MD256 is selected as the clock source for RTC_SLOW_CLK using the Kconfig option
CONFIG_RTC_CLK_SRC_INT_8MD256
, the chip will automatically enter this sub sleep mode during Deep-sleep mode.
Light-sleep:
LSLP_DEFAULT |
LSLP_ADC_TSENS |
LSLP_8MD256 |
LSLP_LEDC8M/ |
|
---|---|---|---|---|
LSLP_XTAL_FPU |
||||
ULP/Touch sensor (ESP32-S2 and ESP32-S3 only) |
Y |
Y |
Y |
Y |
RTC IO input/RTC memory at high temperature |
Y |
Y |
Y |
Y |
ADC_TSEN_MONITOR |
Y |
Y |
Y |
|
8MD256 as the clock source for RTC_SLOW_CLK |
Y |
Y |
||
8 MHz RC clock source used by digital peripherals |
Y |
|||
Keep the XTAL clock on |
Y |
Features: (Also see 8MD256 and ADC_TSEN_MONITOR features for Deep-sleep mode above)
8 MHz RC clock source used by digital peripherals: Currently, only LEDC uses this clock source during Light-sleep mode. When LEDC selects this clock source, this feature is automatically enabled.
Keep the XTAL clock on: Keep the XTAL clock on during Light-sleep mode. Controlled by
ESP_PD_DOMAIN_XTAL
power domain.
ESP32-C2 does not have ADC_TSEN_MONITOR or LSLP_ADC_TSENS feature.
Wakeup Sources
Wakeup sources can be enabled using esp_sleep_enable_X_wakeup
APIs. Wakeup sources are not disabled after wakeup, you can disable them using esp_sleep_disable_wakeup_source()
API if you do not need them any more. See Disable Sleep Wakeup Source.
Following are the wakeup sources supported on ESP32-C2.
Timer
The RTC controller has a built-in timer which can be used to wake up the chip after a predefined amount of time. Time is specified at microsecond precision, but the actual resolution depends on the clock source selected for RTC_SLOW_CLK.
RTC peripherals or RTC memories do not need to be powered on during sleep in this wakeup mode.
esp_sleep_enable_timer_wakeup()
function can be used to enable sleep wakeup using a timer.
GPIO Wakeup
Any IO can be used as the external input to wake up the chip from Light-sleep. Each pin can be individually configured to trigger wakeup on high or low level using the gpio_wakeup_enable()
function. Then the esp_sleep_enable_gpio_wakeup()
function should be called to enable this wakeup source.
Additionally, IOs that are powered by the VDD3P3_RTC power domain can be used to wake up the chip from Deep-sleep. The wakeup pin and wakeup trigger level can be configured by calling esp_deep_sleep_enable_gpio_wakeup()
. The function will enable the Deep-sleep wakeup for the selected pin.
UART Wakeup (Light-sleep Only)
When ESP32-C2 receives UART input from external devices, it is often necessary to wake up the chip when input data is available. The UART peripheral contains a feature which allows waking up the chip from Light-sleep when a certain number of positive edges on RX pin are seen. This number of positive edges can be set using uart_set_wakeup_threshold()
function. Note that the character which triggers wakeup (and any characters before it) will not be received by the UART after wakeup. This means that the external device typically needs to send an extra character to the ESP32-C2 to trigger wakeup before sending the data.
esp_sleep_enable_uart_wakeup()
function can be used to enable this wakeup source.
After waking-up from UART, you should send some extra data through the UART port in Active mode, so that the internal wakeup indication signal can be cleared. Otherwises, the next UART wake-up would trigger with two less rising edges than the configured threshold value.
Disable Sleep Wakeup Source
Previously configured wakeup sources can be disabled later using esp_sleep_disable_wakeup_source()
API. This function deactivates trigger for the given wakeup source. Additionally, it can disable all triggers if the argument is ESP_SLEEP_WAKEUP_ALL
.
Power-down Options
The application can force specific powerdown modes for RTC peripherals and RTC memories. In Deep-sleep mode, we can also isolate some IOs to further reduce current consumption.
Power-down of RTC Peripherals and Memories
By default, esp_deep_sleep_start()
and esp_light_sleep_start()
functions power down all RTC power domains which are not needed by the enabled wakeup sources. To override this behaviour, esp_sleep_pd_config()
function is provided.
Power-down of Flash
By default, to avoid potential issues, esp_light_sleep_start()
function does not power down flash. To be more specific, it takes time to power down the flash and during this period the system may be woken up, which then actually powers up the flash before this flash could be powered down completely. As a result, there is a chance that the flash may not work properly.
So, in theory, it is ok if you only wake up the system after the flash is completely powered down. However, in reality, the flash power-down period can be hard to predict (for example, this period can be much longer when you add filter capacitors to the flash's power supply circuit) and uncontrollable (for example, the asynchronous wake-up signals make the actual sleep time uncontrollable).
Warning
If a filter capacitor is added to your flash power supply circuit, please do everything possible to avoid powering down flash.
Therefore, it is recommended not to power down flash when using ESP-IDF. For power-sensitive applications, it is recommended to use Kconfig option CONFIG_ESP_SLEEP_FLASH_LEAKAGE_WORKAROUND to reduce the power consumption of the flash during Light-sleep, instead of powering down the flash.
However, for those who have fully understood the risk and are still willing to power down the flash to further reduce the power consumption, please check the following mechanisms:
Setting Kconfig option CONFIG_ESP_SLEEP_POWER_DOWN_FLASH only powers down the flash when the RTC timer is the only wake-up source and the sleep time is longer than the flash power-down period.
Calling
esp_sleep_pd_config(ESP_PD_DOMAIN_VDDSDIO, ESP_PD_OPTION_OFF)
powers down flash when the RTC timer is not enabled as a wakeup source or the sleep time is longer than the flash power-down period.
Note
ESP-IDF does not provide any mechanism that can power down the flash in all conditions when Light-sleep.
esp_deep_sleep_start()
function forces power down flash regardless of user configuration.
Configuring IOs (Deep-sleep Only)
Some ESP32-C2 IOs have internal pullups or pulldowns, which are enabled by default. If an external circuit drives this pin in Deep-sleep mode, current consumption may increase due to current flowing through these pullups and pulldowns.
- In Deep-sleep mode:
digital GPIOs (GPIO6 ~ 21) are in a high impedance state.
- RTC GPIOs (GPIO0 ~ 5) can be in the following states, depending on their hold function enabled or not:
if the hold function is not enabled, RTC GPIOs will be in a high impedance state.
if the hold function is enabled, RTC GPIOs will retain the pin state latched at that hold moment.
Entering Sleep
esp_light_sleep_start()
or esp_deep_sleep_start()
functions can be used to enter Light-sleep or Deep-sleep modes correspondingly. After that, the system configures the parameters of RTC controller according to the requested wakeup sources and power-down options.
It is also possible to enter sleep modes with no wakeup sources configured. In this case, the chip will be in sleep modes indefinitely until external reset is applied.
UART Output Handling
Before entering sleep mode, esp_deep_sleep_start()
will flush the contents of UART FIFOs.
When entering Light-sleep mode using esp_light_sleep_start()
, UART FIFOs will not be flushed. Instead, UART output will be suspended, and remaining characters in the FIFO will be sent out after wakeup from Light-sleep.
Checking Sleep Wakeup Cause
esp_sleep_get_wakeup_cause()
function can be used to check which wakeup source has triggered wakeup from sleep mode.
Application Examples
protocols/sntp demonstrates the implementation of basic functionality of Deep-sleep, where ESP module is periodically waken up to retrieve time from NTP server.
wifi/power_save demonstrates the usage of Wi-Fi Modem-sleep mode and automatic Light-sleep feature to maintain Wi-Fi connections.
bluetooth/nimble/power_save demonstrates the usage of Bluetooth Modem-sleep mode and automatic Light-sleep feature to maintain Bluetooth connections.
system/deep_sleep demonstrates the usage of Deep-sleep wakeup triggered by various sources, such as the RTC timer, GPIOs, EXT0, EXT1, the touch sensor, supported by ESP32-C2.
system/light_sleep demonstrates the usage of Light-sleep wakeup triggered by various sources, such as the timer, GPIOs, the touch sensor, supported by ESP32-C2.
API Reference
Header File
This header file can be included with:
#include "esp_sleep.h"
Functions
-
esp_err_t esp_sleep_disable_wakeup_source(esp_sleep_source_t source)
Disable wakeup source.
This function is used to deactivate wake up trigger for source defined as parameter of the function.
See docs/sleep-modes.rst for details.
Note
This function does not modify wake up configuration in RTC. It will be performed in esp_deep_sleep_start/esp_light_sleep_start function.
- Parameters
source -- - number of source to disable of type esp_sleep_source_t
- Returns
ESP_OK on success
ESP_ERR_INVALID_STATE if trigger was not active
-
esp_err_t esp_sleep_enable_timer_wakeup(uint64_t time_in_us)
Enable wakeup by timer.
- Parameters
time_in_us -- time before wakeup, in microseconds
- Returns
ESP_OK on success
ESP_ERR_INVALID_ARG if value is out of range (TBD)
-
bool esp_sleep_is_valid_wakeup_gpio(gpio_num_t gpio_num)
Returns true if a GPIO number is valid for use as wakeup source.
Note
For SoCs with RTC IO capability, this can be any valid RTC IO input pin.
- Parameters
gpio_num -- Number of the GPIO to test for wakeup source capability
- Returns
True if this GPIO number will be accepted as a sleep wakeup source.
-
esp_err_t esp_deep_sleep_enable_gpio_wakeup(uint64_t gpio_pin_mask, esp_deepsleep_gpio_wake_up_mode_t mode)
Enable wakeup using specific gpio pins.
This function enables an IO pin to wake up the chip from deep sleep.
Note
This function does not modify pin configuration. The pins are configured inside esp_deep_sleep_start, immediately before entering sleep mode.
Note
You don't need to worry about pull-up or pull-down resistors before using this function because the ESP_SLEEP_GPIO_ENABLE_INTERNAL_RESISTORS option is enabled by default. It will automatically set pull-up or pull-down resistors internally in esp_deep_sleep_start based on the wakeup mode. However, when using external pull-up or pull-down resistors, please be sure to disable the ESP_SLEEP_GPIO_ENABLE_INTERNAL_RESISTORS option, as the combination of internal and external resistors may cause interference. BTW, when you use low level to wake up the chip, we strongly recommend you to add external resistors (pull-up).
- Parameters
gpio_pin_mask -- Bit mask of GPIO numbers which will cause wakeup. Only GPIOs which have RTC functionality (pads that powered by VDD3P3_RTC) can be used in this bit map.
mode -- Select logic function used to determine wakeup condition:
ESP_GPIO_WAKEUP_GPIO_LOW: wake up when the gpio turn to low.
ESP_GPIO_WAKEUP_GPIO_HIGH: wake up when the gpio turn to high.
- Returns
ESP_OK on success
ESP_ERR_INVALID_ARG if the mask contains any invalid deep sleep wakeup pin or wakeup mode is invalid
-
esp_err_t esp_sleep_enable_gpio_wakeup(void)
Enable wakeup from light sleep using GPIOs.
Each GPIO supports wakeup function, which can be triggered on either low level or high level. Unlike EXT0 and EXT1 wakeup sources, this method can be used both for all IOs: RTC IOs and digital IOs. It can only be used to wakeup from light sleep though.
To enable wakeup, first call gpio_wakeup_enable, specifying gpio number and wakeup level, for each GPIO which is used for wakeup. Then call this function to enable wakeup feature.
Note
On ESP32, GPIO wakeup source can not be used together with touch or ULP wakeup sources.
- Returns
ESP_OK on success
ESP_ERR_INVALID_STATE if wakeup triggers conflict
-
esp_err_t esp_sleep_enable_uart_wakeup(int uart_num)
Enable wakeup from light sleep using UART.
Use uart_set_wakeup_threshold function to configure UART wakeup threshold.
Wakeup from light sleep takes some time, so not every character sent to the UART can be received by the application.
Note
ESP32 does not support wakeup from UART2.
- Parameters
uart_num -- UART port to wake up from
- Returns
ESP_OK on success
ESP_ERR_INVALID_ARG if wakeup from given UART is not supported
-
esp_err_t esp_sleep_enable_bt_wakeup(void)
Enable wakeup by bluetooth.
- Returns
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if wakeup from bluetooth is not supported
-
esp_err_t esp_sleep_disable_bt_wakeup(void)
Disable wakeup by bluetooth.
- Returns
ESP_OK on success
ESP_ERR_NOT_SUPPORTED if wakeup from bluetooth is not supported
-
esp_err_t esp_sleep_disable_wifi_wakeup(void)
Disable wakeup by WiFi MAC.
- Returns
ESP_OK on success
-
esp_err_t esp_sleep_enable_wifi_beacon_wakeup(void)
Enable beacon wakeup by WiFi MAC, it will wake up the system into modem state.
- Returns
ESP_OK on success
-
esp_err_t esp_sleep_disable_wifi_beacon_wakeup(void)
Disable beacon wakeup by WiFi MAC.
- Returns
ESP_OK on success
-
uint64_t esp_sleep_get_ext1_wakeup_status(void)
Get the bit mask of GPIOs which caused wakeup (ext1)
If wakeup was caused by another source, this function will return 0.
- Returns
bit mask, if GPIOn caused wakeup, BIT(n) will be set
-
uint64_t esp_sleep_get_gpio_wakeup_status(void)
Get the bit mask of GPIOs which caused wakeup (gpio)
If wakeup was caused by another source, this function will return 0.
- Returns
bit mask, if GPIOn caused wakeup, BIT(n) will be set
-
esp_err_t esp_sleep_pd_config(esp_sleep_pd_domain_t domain, esp_sleep_pd_option_t option)
Set power down mode for an RTC power domain in sleep mode.
If not set set using this API, all power domains default to ESP_PD_OPTION_AUTO.
- Parameters
domain -- power domain to configure
option -- power down option (ESP_PD_OPTION_OFF, ESP_PD_OPTION_ON, or ESP_PD_OPTION_AUTO)
- Returns
ESP_OK on success
ESP_ERR_INVALID_ARG if either of the arguments is out of range
-
esp_err_t esp_deep_sleep_try_to_start(void)
Enter deep sleep with the configured wakeup options.
The reason for the rejection can be such as a short sleep time.
Note
In general, the function does not return, but if the sleep is rejected, then it returns from it.
- Returns
No return - If the sleep is not rejected.
ESP_ERR_SLEEP_REJECT sleep request is rejected(wakeup source set before the sleep request)
-
void esp_deep_sleep_start(void)
Enter deep sleep with the configured wakeup options.
Note
The function does not do a return (no rejection). Even if wakeup source set before the sleep request it goes to deep sleep anyway.
-
esp_err_t esp_light_sleep_start(void)
Enter light sleep with the configured wakeup options.
- Returns
ESP_OK on success (returned after wakeup)
ESP_ERR_SLEEP_REJECT sleep request is rejected(wakeup source set before the sleep request)
ESP_ERR_SLEEP_TOO_SHORT_SLEEP_DURATION after deducting the sleep flow overhead, the final sleep duration is too short to cover the minimum sleep duration of the chip, when rtc timer wakeup source enabled
-
esp_err_t esp_deep_sleep_try(uint64_t time_in_us)
Enter deep-sleep mode.
The device will automatically wake up after the deep-sleep time Upon waking up, the device calls deep sleep wake stub, and then proceeds to load application.
Call to this function is equivalent to a call to esp_deep_sleep_enable_timer_wakeup followed by a call to esp_deep_sleep_start.
The reason for the rejection can be such as a short sleep time.
Note
In general, the function does not return, but if the sleep is rejected, then it returns from it.
- Parameters
time_in_us -- deep-sleep time, unit: microsecond
- Returns
No return - If the sleep is not rejected.
ESP_ERR_SLEEP_REJECT sleep request is rejected(wakeup source set before the sleep request)
-
void esp_deep_sleep(uint64_t time_in_us)
Enter deep-sleep mode.
The device will automatically wake up after the deep-sleep time Upon waking up, the device calls deep sleep wake stub, and then proceeds to load application.
Call to this function is equivalent to a call to esp_deep_sleep_enable_timer_wakeup followed by a call to esp_deep_sleep_start.
Note
The function does not do a return (no rejection).. Even if wakeup source set before the sleep request it goes to deep sleep anyway.
- Parameters
time_in_us -- deep-sleep time, unit: microsecond
-
esp_err_t esp_deep_sleep_register_hook(esp_deep_sleep_cb_t new_dslp_cb)
Register a callback to be called from the deep sleep prepare.
Warning
deepsleep callbacks should without parameters, and MUST NOT, UNDER ANY CIRCUMSTANCES, CALL A FUNCTION THAT MIGHT BLOCK.
- Parameters
new_dslp_cb -- Callback to be called
- Returns
ESP_OK: Callback registered to the deepsleep misc_modules_sleep_prepare
ESP_ERR_NO_MEM: No more hook space for register the callback
-
void esp_deep_sleep_deregister_hook(esp_deep_sleep_cb_t old_dslp_cb)
Unregister an deepsleep callback.
- Parameters
old_dslp_cb -- Callback to be unregistered
-
esp_sleep_wakeup_cause_t esp_sleep_get_wakeup_cause(void)
Get the wakeup source which caused wakeup from sleep.
- Returns
cause of wake up from last sleep (deep sleep or light sleep)
-
void esp_wake_deep_sleep(void)
Default stub to run on wake from deep sleep.
Allows for executing code immediately on wake from sleep, before the software bootloader or ESP-IDF app has started up.
This function is weak-linked, so you can implement your own version to run code immediately when the chip wakes from sleep.
See docs/deep-sleep-stub.rst for details.
-
void esp_set_deep_sleep_wake_stub(esp_deep_sleep_wake_stub_fn_t new_stub)
Install a new stub at runtime to run on wake from deep sleep.
If implementing esp_wake_deep_sleep() then it is not necessary to call this function.
However, it is possible to call this function to substitute a different deep sleep stub. Any function used as a deep sleep stub must be marked RTC_IRAM_ATTR, and must obey the same rules given for esp_wake_deep_sleep().
-
void esp_set_deep_sleep_wake_stub_default_entry(void)
Set wake stub entry to default
esp_wake_stub_entry
-
esp_deep_sleep_wake_stub_fn_t esp_get_deep_sleep_wake_stub(void)
Get current wake from deep sleep stub.
- Returns
Return current wake from deep sleep stub, or NULL if no stub is installed.
-
void esp_default_wake_deep_sleep(void)
The default esp-idf-provided esp_wake_deep_sleep() stub.
See docs/deep-sleep-stub.rst for details.
-
void esp_deep_sleep_disable_rom_logging(void)
Disable logging from the ROM code after deep sleep.
Using LSB of RTC_STORE4.
-
void esp_sleep_config_gpio_isolate(void)
Configure to isolate all GPIO pins in sleep state.
-
void esp_sleep_enable_gpio_switch(bool enable)
Enable or disable GPIO pins status switching between slept status and waked status.
- Parameters
enable -- decide whether to switch status or not
Macros
-
ESP_PD_DOMAIN_RTC8M
-
ESP_SLEEP_POWER_DOWN_CPU
Type Definitions
-
typedef void (*esp_deep_sleep_cb_t)(void)
-
typedef esp_sleep_source_t esp_sleep_wakeup_cause_t
-
typedef void (*esp_deep_sleep_wake_stub_fn_t)(void)
Function type for stub to run on wake from sleep.
Enumerations
-
enum esp_deepsleep_gpio_wake_up_mode_t
Logic function used for EXT1 wakeup mode.
Values:
-
enumerator ESP_GPIO_WAKEUP_GPIO_LOW
-
enumerator ESP_GPIO_WAKEUP_GPIO_HIGH
-
enumerator ESP_GPIO_WAKEUP_GPIO_LOW
-
enum esp_sleep_pd_domain_t
Power domains which can be powered down in sleep mode.
Values:
-
enumerator ESP_PD_DOMAIN_XTAL
XTAL oscillator.
-
enumerator ESP_PD_DOMAIN_RC_FAST
Internal Fast oscillator.
-
enumerator ESP_PD_DOMAIN_VDDSDIO
VDD_SDIO.
-
enumerator ESP_PD_DOMAIN_MAX
Number of domains.
-
enumerator ESP_PD_DOMAIN_XTAL
-
enum esp_sleep_pd_option_t
Power down options.
Values:
-
enumerator ESP_PD_OPTION_OFF
Power down the power domain in sleep mode.
-
enumerator ESP_PD_OPTION_ON
Keep power domain enabled during sleep mode.
-
enumerator ESP_PD_OPTION_AUTO
Keep power domain enabled in sleep mode, if it is needed by one of the wakeup options. Otherwise power it down.
-
enumerator ESP_PD_OPTION_OFF
-
enum esp_sleep_source_t
Sleep wakeup cause.
Values:
-
enumerator ESP_SLEEP_WAKEUP_UNDEFINED
In case of deep sleep, reset was not caused by exit from deep sleep.
-
enumerator ESP_SLEEP_WAKEUP_ALL
Not a wakeup cause, used to disable all wakeup sources with esp_sleep_disable_wakeup_source.
-
enumerator ESP_SLEEP_WAKEUP_EXT0
Wakeup caused by external signal using RTC_IO.
-
enumerator ESP_SLEEP_WAKEUP_EXT1
Wakeup caused by external signal using RTC_CNTL.
-
enumerator ESP_SLEEP_WAKEUP_TIMER
Wakeup caused by timer.
-
enumerator ESP_SLEEP_WAKEUP_TOUCHPAD
Wakeup caused by touchpad.
-
enumerator ESP_SLEEP_WAKEUP_ULP
Wakeup caused by ULP program.
-
enumerator ESP_SLEEP_WAKEUP_GPIO
Wakeup caused by GPIO (light sleep only on ESP32, S2 and S3)
-
enumerator ESP_SLEEP_WAKEUP_UART
Wakeup caused by UART (light sleep only)
-
enumerator ESP_SLEEP_WAKEUP_WIFI
Wakeup caused by WIFI (light sleep only)
-
enumerator ESP_SLEEP_WAKEUP_COCPU
Wakeup caused by COCPU int.
-
enumerator ESP_SLEEP_WAKEUP_COCPU_TRAP_TRIG
Wakeup caused by COCPU crash.
-
enumerator ESP_SLEEP_WAKEUP_BT
Wakeup caused by BT (light sleep only)
-
enumerator ESP_SLEEP_WAKEUP_VAD
Wakeup caused by VAD.
-
enumerator ESP_SLEEP_WAKEUP_UNDEFINED